In such tape magazines an unused section of test tape is pulled from a supply reel and guided over a receiving device where it takes up a sample of body fluid. Afterwards the section of test tape which is now used is wound onto a waste reel. A detection device which measures the sample and transfers the result of the measurement to an evaluation device is attached to the receiving unit.
Such tape magazines are preferably used in blood sugar measuring instruments for diabetics who depend on a continuous monitoring of their blood sugar values. The test tape allows a blood sugar test to be carried out inside the instrument after applying capillary blood for example from a finger pad. For this purpose a plurality of test sections or test fields are arranged consecutively on the test tape. An unused section of tape is moved into an active position by advancing the tape. Then the capillary blood is applied and analyzed. In order to simply dose very small amounts of blood and to position the test tape as exactly as possible relative to the detection device, the test tape is guided over a deflecting head inside the instrument. In this process there is a risk of erroneous measurements if the test tape slips off the deflecting head. For a successful measurement the test tape must remain at a well-defined position and rest against it evenly while maintaining a predetermined distance to the detection unit. This is necessary for at least as long as it takes to complete the measurement. Another challenge is that the test tape is very sensitive to contamination. Hence the unused area of the test tape should be spatially separated from the used area and also be screened from external influences which could impair the function of the test tape. Hence a direct drive coupling between the storage unit and the waste unit is very difficult.
Furthermore the hand-held devices of the prior art are designed for continuous use whereas the tape magazine is replaced. The hand-held devices are therefore relatively large and quite laborious to manufacture not least due to the complicated instrument technology.